35 



The Use of Fertilizers on Grass Lands. 



Top-dressing grass lands was discussed at some lengtii in the first 

 paper on tliis subject. The reasons were therein given why it is be- 

 lieved that on most farms manures should generally be used on the 

 tilled fields. It was pointed out that in the decay of manures on the 

 surface there is some risk of loss of their most valuable constituent, — 

 nitrogen. It is equally true that in the decay of organic fertilizers, 

 such as dried blood, dry gi-ound fish or tankage on the surface there is 

 danger of similar loss through the escape of ammonia into the air. 



Nitrate of Soda for MoiviJigs. — It seems to be the almost universal 

 experience that nitrate of soda is the most valuable fertilizer which can 

 be used for the purpose of increasing the growth of the grasses propei*. 

 Grasses make most of their growth in the early part of the season, and 

 at a time when the conditions are not very favorable for the conversion 

 of the relatively unavailable constituents of such fertilizers as sulfate of 

 ammonia and the organic fertilizers which have just been mentioned 

 into compounds suitable for plant food. Nitrate of soda, as is now 

 generally known, is in condition to feed the ci'op just as soon as it is 

 brought into solution, and relatively' light rains will dissolve it and 

 carry it into the soil. Nitrate of soda is, however, so soluble that there 

 is quite a possibility that under some conditions it may be washed 

 through the soil and lost before the crop can utilize it. This danger is 

 undonljtedlv less in the case of the grass crop than with most others, 

 for the grass roots absolutely fill the soil, and the soil itself is in a rela- 

 tively compact condition, — unfavorable to the rapid percolation of 

 water. The writer has in a number of instances seen unmistakable 

 evidence, in the second season following its application, of the beneficial 

 effects of a heavy dressing of nitrate of soda. This observation, how- 

 ever, was made upon soils containing a large proportion of very fine 

 particles, and therefore natui'ally compact and relatively impermeable. 

 Even in the case of such soils, however, much care should be taken to 

 apply nitrate of soda as near as possible at the time when the crop is 

 ready to make use of it It would be a mistake, especially in the case 

 of the lighter soils, to apply nitrate of soda in early spring. It should 

 be held until the weather is fairly settled and the grass is beginning to 

 make considerable growth. In average seasons from about the 1st to the 

 10th of May will probably be found to give the largest increases in the 

 crop. The quantity of nitrate of soda which may wisely be used in top- 

 dressing mowings doubtless varies widely with soils. VVheeler finds that 

 in Rhode Island applications running up to 300 or 350 pounds per acre 

 prove profitable, and, indeed, that there is a larger profit from the use 

 of such amounts than follows the use of smaller quantities. On some 

 soils — and many of the fields of the college farm seem to have soils of 

 this character — so heavy an application would usually prove inadvis- 

 able ; it would render the crop likely to lodge. It has been found on 

 the college farm that about 200 pounds per acre seem to be as large a 

 quantity as it will pay to use. There must, of course, as will be at once 

 understood, be a wide dift'erence in the tendency to lodge under heavy 

 nitrate manuring with the season, and no doubt also with the species of 

 grass. In relatively dry seasons the heavy applications may prove 

 useful, but in seasons characterized by frequent and suiticient rainfalls 

 moi'e moderate applications seem preferable. AVheeler has pointed 

 out, as also have others, that the hay produced under heavy applications 

 of nitrate of soda is richer in protein than that produced where less 

 nitrate is used ; but if the more liberal use of nitrate is followed by the 

 lodging of the crop, the loss in quality due to the conditions existing 

 must more than oft'set any gain due to the greater protein content. 



Should Nitrate of Soda be used alone in Top-dressing Mowings'} — In 

 cases where a mowing is used in rotation for hoed crops, and where the 



